Week 5 EENT Flashcards
Describe the layers of the eye.
- Sclera: thick fibrous opaque outer layer.
Composed of dense connective tissue, transparent at the cornea (allows light to enter the eye) .
Protects eye, provides shape, attachment point for ocular muscles.
Visible exterior surface of slcera and inner eyelids are lined with conjunctiva (mucous membrane).
2.Uvea: middle vascular layer, consists of iris+ ciliary body +choroid.
Choroid is deeply pigmented (melanin), highly vascular connective tissue layer. Prevents light from scattering inside the eye, and provides nutrients/O2.
Anterior part of choroid includes iris (controls pupil size) and ciliary body (produces aqueous humor, and controls lens shape for accommodation [near/far vision]).
- Retina: innermost light-sensitive layer of nervous tissue.
Millions special sensory cells, or photoreceptors called rods & cones.
Rods: peripheral + dim light vision (black&white), densest @ periphery
Cones: color + detail vision, densest @ center of retina.
Rods and cones transmit impulses to nerve cells in retina–> optical nerve–> visual cortex
Huether p. 349
Describe the formation and flow of aqueous humour.
What is the fx of the aqueous humor?
What happens if flow is blocked?
Secreted by the ciliary processes
Fills the aqueous chamber and helps keep pressure inside the eye, as well as supply nutrients to the lens and cornea.
Reabsorbed into the scleral venous sinus.
Intraocular pressure increases if a blockage occurs (causing glaucoma)
In which structure of the eye are rods and cones found? What do they do?
Found at the back of the retina in the photosensitive region.
Rods: More sensitive to light and the receptors for low-light conditions.
Cones: Less sensitive to light but highly sensitive to red, green, and blue regions of the visual spectrum.
What is the “blind spot” in our eye, and why?
The optic disc, in the retina, has no rods or cones.
Describe the structure of the retina and their function.
The Retina is the inner layer of the eye.
Consists of:
-Neural (Optic) Retina (Sensitive to light) (at the back of the eye). This is composed of the outer retinal pigmented epithelium (lying adjacent to the vascular choroid) and the photosensitive region of rods (more sensitive to light and the receptors for low-light conditions) and cones (less sensitive to light but highly sensitive to red, green, and blue regions of the visual spectrum).
-Optic Disc: no rods or cones (therefore, our blind spot).
-Fovea centralis, which is the central focusing area. It is the most sensitive portion because it is thin and most layers of the retina are absent. It consists only of cones, specialized for colour vision and acute discrimination.
-Nonvisual Retina: Lines the internal surface of the ciliary body and iris at the front of the eye .
How do images transfer from eye to brain?
The Retina has interspersed layers of conducting and association neurons .
Axons of ganglion cells convey the photosensory info to the Optic disc. This information is then transmitted to the optic nerve and relayed centrally.
What is a detached retina?
A retinal detachment is a tear or break in the retina with build-up of fluid and separation from underlying tissue.
What are risk factors associated with increased risk of retinal detachment?
Extreme myopia (nearsightedness), previous cataract surgery, ocular trauma, diabetic retinopathy, sick cell disease, family history of retinal detachment.
What are the signs and symptoms of retinal detachment?
Painless vision disturbance/ loss
Early: floaters, flashes of light, blurred vision
Progresses to: curtain/ greyness over visual field, decreased peripheral or central vision
Describe the 5 common origins of epistaxis(etiology and location).
- Hereditary hemorrhagic telangiectasia (HHT), also known as Osler Weber Rendu syndrome, is a genetically inherited condition. People with HHT have small blood vessel malformations, known as telangiectasias, which affect the skin and mucosal membranes. Nosebleeds are the most common symptom; between 50 percent and 80 percent have recurrent bleeds.
- Spontaneous epistaxis usually occurs in the fifth decade of life and may be associated with hypertension or liver insufficiency. This type of nosebleed resolves without medical treatment; however, in some patients, the intensity or repetition of hemorrhages in a short period of time may require more invasive nosebleed treatment such as embolization.
- Trauma
- Tumors. Occasionally bleeding from the nasal or oral cavities may be related to the presence of a tumor. If there is concern for this, further imaging such as computer tomography scan or magnetic resonance imaging to evaluate what is happening.
5.Vascular Malformations
What are the treatment options for persistent epistaxis?
1st step - “packing” the nose, which should be performed by an appropriately trained physician. If this does not stop the bleeding
2nd step - embolization is performed by which the blood vessel supplying the inner lining of the nose is blocked.
Embolization can be used to treat severe, recurring nosebleeds that cannot be controlled by traditional means.
- Can investigate the source of the bleeding via angiography. After we identify the vessels responsible for the bleeding, we can go back in through a catheter and block the vessels to stop the bleeding (embolization). In some cases, this technique can be lifesaving.
What are some adverse outcomes from prolonged persistent/recurrent epistaxis?
If you experience severe blood loss from a nosebleed, it can cause serious anemia or cardiac dysfunction and reduced quality of life.
What condition are we referring to below?
-One of the most commonly seen eye conditions.
-More common in adults than children; prevalence increases with age.
-Risk factors: diabetes, candida, seborrheic dermatitis, acne rosacea, contact lens use, retinoids, chemo agents
-Inflammation of eyelid, can be acute or chronic.
Blepharitis
What are the 3 main causes of’; blepharitis?
- Staphylococcus -most common colonizing bacteria, responsible for bacterial infection of lid margin
- Inflammatory skin conditions:
-seborrheic dermatitis: excessive shedding of skin cells and blockage of glands
-rosacea, eczema, psoriasis
-contact dermatitis (i.e., due to irritant such as cosmetics) - Meibomian gland dysfunction -modified sebaceous gland, responsible for secretion of oily layer of tear film (critical for eye lubrication); altered gland function provides and environment that promotes bacterial growth
What are the signs and symptoms you might see with blepharitis?
-bilateral condition, but may have asymmetric findings
-erythema, edema, flaking/ scales of eyelid
-burning, itching, dryness and flaking of eyelid margin
-tearing, dry eyes, crusting/matting of eyelashes in morning
-photophobia
-recurrent eye infections, styes, or chalazions
-rarely causes problems with vision, however, can occur with conjunctival irritation
Staphylococcus: erythema/ edema, scaling, burning, tearing, itching, recurrent styes
Seborrheic: lid margin swelling and erythema, flaking, nasolabial erythema, scaling
How is blepharitis diagnosed?
What are some differential diagnoses to consider?
Diagnosis is based on clinical picture (erythema, irritation, crusting/ flakes on eyelid)
-differentiate between bacterial infection or inflammatory skin condition/ disease
Ddx: conjunctivitis, eyelid malignancy, stye or chalazion, URTI, sinusitis
Discuss treatment and management considerations for a patient diagnosed with blepharitis.
-assess for vision changes
-f/u with ophthalmology for recurrent episodes, impaired vision or corneal abnormalities
-all patients should follow up with primary provider in 1-2 weeks
Eyelid hygiene:
-wash eye with antibacterial soap and water (or gentle baby shampoo)
-apply warm compress to eye (comfort and liquifies secretions)
-lid massage in circular motion towards eye
-use clean washcloth or gauze to clean along lash line
-stop use of contacts until healed
Pharmacological:
-usually if mild/ mod, good eyelid hygiene is all that is needed
-for severe/ chronic, consider antibiotics
Topical bacitracin or erythromycin ophthalmic ointment to margin of eye at bedtime
Oral antibiotics: tetracycline (not for peds under 8, pregnant or lactating women) or doxycycline (alternative: erythromycin or azithromycin)
What age group is tonsillitis most seen in, and why?
Tonsillitis most often affects children, and tonsillitis caused by bacteria is most common in children ages 5 to 15.
Frequent exposure to germs. School-age children are in close contact with their peers and frequently exposed to viruses or bacteria that can cause tonsillitis.
The tonsils are the immune system’s first line of defense against bacteria and viruses that enter your mouth. This function may make the tonsils particularly vulnerable to infection and inflammation. However, the tonsil’s immune system function declines after puberty — a factor that may account for the rare cases of tonsillitis in adults.
What it the time course for tonsillitis?
What are the common causes of tonsillitis?
The time course is 7-10 days.
Tonsillitis is most often caused by common viruses, but bacterial infections also can be the cause. The most common bacterium causing tonsillitis is Streptococcus pyogenes (group A streptococcus), the bacterium that causes strep throat. Other strains of strep and other bacteria also may cause tonsillitis.
Common s/s of tonsillitis include:
Red, swollen tonsils
White or yellow coating or patches on the tonsils
Sore throat and painful swallowing
Fever
Enlarged, tender glands (lymph nodes) in the neck
A scratchy, muffled or throaty voice
Neck pain or stiff neck
Headache
What s/s might you see with tonsillitis in young children unable to describe how they are feeling?
Drooling due to difficult or painful swallowing
Refusal to eat
Unusual fussiness
What are tonsillitis s/s that are of increasing concern?
A sore throat with fever
A sore throat that doesn’t go away within 24 to 48 hours
Painful or difficult swallowing
Extreme weakness, fatigue or fussiness
Difficulty breathing
Extreme difficulty swallowing
Excessive drooling
What are some possible advanced tonsillitis complications?
Disrupted breathing during sleep (obstructive sleep apnea)
Infection that spreads deep into surrounding tissue (tonsillar cellulitis)
Infection that results in a collection of pus behind a tonsil (peritonsillar abscess)
Gayle’s note - I took this from an ILO illness script that stated these are ‘chronic’ complications, but I disagree so I labelled them ‘advanced’ complications. Then I checked UTD and they are called ‘suppurative’ complications.
They also list Otitis media.
Tonsillitis due to streptococcus that is not properly treated has an increased chance of manifesting into these rare disorders.
- Rheumatic fever, a serious inflammatory condition that can affect the heart, joints, nervous system and skin
- Complications of scarlet fever, a streptococcal infection characterized by a prominent rash
- Inflammation of the kidney (poststreptococcal glomerulonephritis)
- Poststreptococcal reactive arthritis, a condition that causes inflammation of the joints
How is strep throat diagnosed?
- Diagnosis is based on physical exam (pt history, symptoms), swollen lymph nodes, characteristics of tonsils. (Gayle’s addition: sore throat score)
- Throat swab
- Complete blood cell count (CBC): can indicate whether an infection is more caused by a bacterial or viral agent. A CBC is not often needed to diagnose strep throat. However, if the strep throat lab test is negative, the CBC may be needed to help determine the cause of tonsillitis.
What are the treatment recommendations for someone you’ve diagnosed with strep throat?
Antibiotics if warranted. Teachings re: importance of finishing course.
Encourage rest
Adequate fluids
Comforting foods and beverage. Warm liquids and cold treats can soothe a sore throat.
Saltwater gargles TID
Humidify the air
Offer lozenges. Avoid irritants
Treat pain and fever
Surgery to remove tonsils, once a common procedure to treat tonsillitis, is usually performed only when tonsillitis occurs frequently, doesn’t respond to other treatments or causes serious complication
What is the time course of hordeolum vs. chalazion?
Most hordeola resolve spontaneously over one to two weeks and do not require specific intervention.
Untreated, chalazia may take several weeks to months to resolve
How do the s/s of hordeola differ from those of chalazia?
A hordeolum (stye) is an acute inflammation of the sebaceous glad of eyelid (near eyelash) that presents as a localized painful and erythematous swelling or nodule.
A chalazion is red, swollen, typically painless localized swelling/nodule in eye.
What is the pathophysiology behind external and internal hordeola?
External hordeola arise from glands in the eyelash follicle or lid-margin.
Internal hordeola are caused by inflammation of the meibomian gland, resulting in swelling just under the conjunctival side of the eyelid.
Staphylococcus aureus is the pathogen implicated in most cases, but hordeola can also be sterile.
Hordeola sometimes transform into chalazia after the inflammation resolves.
